Combustion of fuels



Patented Sept. .17, 1935 UNITED STATES PATENT OFFICE 2,o14,cscCOMBUSTION .OF FUELS Eugene Lubovitch and Jean Midor Fieschi, Paris,France; said Fieschi assignor to said Lubovitch No Drawing. ApplicationAugust 18, 1932, Serial No. 629,308. In France August 27 193 12 Claims.

In order to overcome these drawbacks it has been proposed to add to thefuel mixtures of different substances such as metal nitrates or 15chlorates or the oxides of manganese, iron, chro- It has been found,however, that these substances when employed singly or in' the mixturesknown so far have only a comparatively small influence on thecombustion. Besides these 20 were mixed quite-unsystematically as theeffect of the different substances was not recognized and consequentlythere havev been proposed some mixtures, which containedvup to tendifferent components. It is also unknown up to now that 5 mixtures ofthis kind were employed in shaft furnaces where the fuel is brought indirect contact with the material to be treated, undoubtedly because some'of the chemicals commonly used for enhancing the combustion, like thesul- 30 phides or phosphates, would have, a detrimental influence uponthe ore to be melted. We have found that the combustion process may beconsiderably improved by adding mixtures of substances belonging tocertain groups 35 of substances which partly act as oxidizing catalysts,(i. e. substances which, without apparently losing their own oxidecontent to the fuel, nevertheless promote the absorption of theatmospheric oxygen by the fuel); partly as promoters 40 of thecatalysts, (i. e. substances which, without containing themselves anyoxygen, nevertheless seem to increase the catalytic action-of anyoxidizing catalysts present); partly as immediate oxidizing agents origniters (i. e. substances which 45 at the oven temperature yield theirown oxygen to the fuel or the available atmospheric oxygen and by doingso directly accelerate the combustion of the fuel). The action of thesecombined mixtures exceeds by far the efiects which could 50 have beenexpected from-the known action of some of the individual components. Thenew compositions comprise as their main constituents: (1) Oxidesor saltsof the rare earth metals or of metals having properties similar to those55 of the rare earths, such as the. oxides or salts of cerium orthorium, in a form occurring in nature, e. g. in the form of mona'zite,which is a phosphate containing rare earths, or as an artificialproduct. Besides these substances the oxides of barium must be mentionedas especially potent- 5 oxidizing catalysts, whose use is equivalent tothat of the oxides of rare earth metals.-

(2) An alkali chloride, such as potassium or sodium chloride, whichpresumably acts as a promoter.

(3) Furthermore, salts having an oxidizing action. These salts in beingdecomposed transfer their oxygen wholly or in part to the fuel and actas promoters of'the catalytical substances'or as igniters or as bothpromoters and igniters.

For instance, the nitrates or permanganates or chlorates of the alkalior alkaline earth metals may be used for such purpose. Different saltsof this kind may be used simultaneously. Some of these substances may beregarded both as immediate oxidizing agents and as oxidizing catalysts,e. g. the alkali or alkaline earth permanganates.

To these main constituents of the new composition of matter, whichrepresent the three abovementioned classes of substances, in the ordernamed, other substances may, or may not be added, namely: h

(4) Compounds of metals which can form differentv degrees of oxidation,for instance the oxides or other derivatives of manganese, iron, 7

lead, copper, or mixtures thereof. All metal salts or oxides mentionedunder 1 and 4 occur in different reversible degrees of oxidation. Theiraction which resembles that of strong catalysts, may be, explained insuch a manner that the lower oxides are temporarily oxidized higher bythe oxygen of the air conducted over or through the hearth or furnace,whereupon the oxygen set free again is transferred to the fuel in thenascent form, e. g. in an especially active form. In this way the metalcompounds are retransformed into the loweroxidized state (or into themetallic state), and the whole process repeats itself continuously,associations and dissociations occurring simultaneously.

Instead of the compounds described above under (1) and (4), suchcompounds may be used, which at the temperature of the hearth or furnaceform the oxides described and required.

The addition of merely a small amount of the new composition issufficient for a considerable amount of fuel, because part of thereaction with the fuel to be consumed is not so much a chemical one inthe ordinary sense, but a catalytic action, where a small amount ofingredients exerts and the like.

. metallurgical furnaces, etc.)

an indefinite eflect, without appreciably lessen ing the amount orchanging the composition of the agents.

The presence of such a mixture facilitates the oxidation of the fuel. Inconsequence thereof the amount of air which up to now had to be suppliedin excess to the hearth or furnace may be greatly diminished. Theincandescent mass is no longer cooled by the-stream of superfluous airand the losses of calories in the waste gases are diminished.

' On the other hand the oxygen, taken up by the added composition fromthe air is given oil to the fuel in the nascent form. In that way thebuming process is highly intensified and a higher temperature is reachedin the glowing mass. For instance, the pressure in a steam boiler israised' more rapidly by using coal with an addition according to ourinvention than with ordinary coal. Gaseous hydrocarbons are by thismethod burnt within the hearth or furnace instead of being drawn offu'nignited by the waste gases.

From the foregoing it becomes evident that a better localized, easierand more complete combustion is obtained with a minimum excess of air.

in this latter. The powdero may be added also in a suitable way in thepreparation of briquettes, agglomerates and the like.

Example As an example, the mixture according to our invention may becomposed as follows:

Per cent Cerium oxide 10 to Barium nitrate to Sodium chloride 40 toOnetotwokilogramsof this mixtureperton of the fuel are sufficient inorder to obtain a far more complete cmnbustion with a minimum excess ofair and to have the other advantages described above. J

The present invention is of special importance for use in shaft furnacesin which the materials to be treated are mixed with the fuel and inwhich the disadvantage of the coal being incompletely oxidized isespecially great. The presence of the new composition has no detrimentalinfluence whatever on the product of the furnace work since it does notcontain any injurlous components such as sulfur, phosphorus,

m scope of applicability of our invention is large and extends overhearths for industrial and home use and different kinds of furnaces(rotary furnaces, so called Hofl'mann furnaces, (annular furnaces forroasting limestone and the like) It is furthermore suitable for everykind of natural or artificial solid, liquid or gaseous fuel.

We claim:

1. A process of improving the. combustion of solid fuels, comprising theaddition to the fuel of a small amount of a mixture containing at leastone alkali chloride, at least one substance selected from the oxides andsalts of cerium and thorium and the oxides of barium and at least onesalt selected from the nitrates, permanganates and chlorates of thealkali and alkaline earth metals.

2. A process of improving the combustion of solid fuels, comprising theaddition to the fuel, of a small amount of a mixture containing at leastone alkali chloride, at least one oxide of barium and at least one saltselected from the nitrates, permanganates and chlorates of the alkaliand alkaline earth metals.

3. A process of improving the combustion of solid fuels, comprising theaddition to the fuel, of a small amount of a mixture containing at leastone alkali chloride, oxide of cerium and at least one salt selected fromthe nitrates, per- 15 manganates and chlorates of the alkali andalkaline earth metals.

4. A process of improving the combustion of a solid fuels, comprisingthe addition to the fuel,

of a small amount of a mixturecontaining at 20 least one alkalichloride, at least one substance selected from the salts of cerium andat least one salt selected from the nitrates, permanga-- nates andchlorates of the alkali and alkaline earth metals.

5. A process of improving the combustion of solid fuels, comprising theaddition to the fuel, of a small amount of a mixture containing at leastone alkali'chloride'at least one substance selected from the oxides andsalts of cerium and 80 thorium and the oxides of barium and at least onesalt, selected from the nitrates, permanganates and chlorates of thealkali and alkaline earth metals and at least one oxide of a metal whichcan form different degrees of oxidation, as selected from the compoundsof manganese, iron, lead and copper.

6. A process of improving the combustion of solid fuels, comprising theaddition to the fuel of a small amount of a mixture containing at 40least one alkali chloride, at least one oxide of barium and at least onesalt, selected from the nitrates, permanganates and chlorates of thealkali and alkaline earth metals and at least one oxide of a metal whichcan form different 45 degrees of oxidation,- selected from the compoundsof manganese, iron, lead and copper. 1

7. A process of improving the combustion of solid fuels, comprising theaddition to the fuel, of a small amount of a mixture containing at 5least one alkali chloride, at least one substance, selected from theoxides and salts of cerium and thorium and at least one salt, selectedfrom'the nitrates; permanganates and chlorates of the alkali andalkaline earth metals and at least 56 one oxide of a metal which canform different degrees of oxidation, selected from the compounds ofmanganese, iron, lead and copper.

8. A process of improving the combustion of solid fuels, comprising theaddition to the fuel, soof a small amount of a mixture containing atleast one alkali chloride, oxide of cerium and at least one salt,selected from the nitrates, per manganates and chlorates ofthe alkaliand alkaline earth metals and at least one oxide of a 06 metal which canform different degrees of oxidation selected from the compounds ofmanganese, iron, lead and copper.

9. A process of improving the combustion of solid fuels, comprising theaddition to the fuel, of a'small amount of-a mixture containing at leastone alkali chloride, atleast one substance, selected'from the salts ofcerium and at least, one salt, selected from the nitrates, permanganatesand chlorates of the alkali and alkaline ll earth metals and at leastone oxide of a metal which can form diflerent degrees of oxidation,selected from the compounds of manganese, iron, lead and copper.

10. A process of improving the combustion of solid fuels, comprising theaddition to the fuel, of a small amount of a mixture containing at leastone alkali chloride, at least one substance, selected from the salts ofcerium, and at least one salt, selected from the nitrates, permanganates and chlorates of the alkali and alkaline earth metals and at leastone oxide of a metal which can form different degrees of oxidation,selected from the compounds of manganese, iron, leadand copper.

11. A process of improving the combustion of solid fuels, comprising theaddition to the fuel,

of a small amount of a mixture containing at least one alkali chloride,monazite, and at least one salt selected from the nitrates,permanganates and chlorates of the alkali and alkaline earth metals.

12. A process of improving the combustion of solid fuels, compris n theaddition to the fuel. of a'small amount of a mixture containing at leastone alkali chloride, monazite, and at least one salt, selected'from thenitrates, permanga- 10 nates and chlorates of the alkali and alkalineearth metals and at least one oxide of a metal which can form differentdegrees of oxidation, selected from the oxides of manganese, iron, leadand coppe 15 EUGENE LUBOVI'I'CH. 'JEAN MIDOR FIESC'HI.

